In present day technology, wherein MOSIC circuitry is employed in a variety of electronic circuits, recent improvements have been directed into incorporating all of the circuit elements which are necessary for small-sized calculators into a single semiconductor chip. As one type of circuit which may be so constructed, a clock pulse generator circuit, made up of a closed-loop arrangement of three inverters and capacitors connected therebetween has been developed. This circuit is described in U.S. patent application entitled Pulse Generator Ser. No. 433,483 filed Jan. 15, 1974 by S. Shimada et al. and assigned to the assignee of the present application, and relates to the subject matter of Japanese priority application No. 6, 1971/73 filed in Japan on June 4, 1973.
One of the problems associated with such electronic circuitry is the instability of the same due to changes in ambient temperature and the power supply voltage therefor. Moreover, when electronic circuits are manufactured in the form of MOSIC structure, the oscillating periods among the variously manufactured MOSICs will vary over a wide range due to the differences in the characteristics of the respective circuits.
As a result, some form of compensation is necessary to prevent this instability and to compensate for the differences of the oscillating periods among the mass-produced pulse generator MOSICs.